Mettenberger's medical concerns could drop him into the third day of the draft. (Greg Nelson/SI/Getty Images)

It has been a rough few days for former LSU quarterback Zach Mettenberger, and more bad news couldn't come at a worse time. Just over 24 hours before the start of the 2014 NFL draft and not long after word got out that Mettenberger submitted a diluted urine sample at the NFL Scouting Combine, reports have surfaced that Mettenberger's back has been red-flagged by teams around the league because of a condition called spondylolysis.

Spondylolysis is a stress fracture of one of the vertebrae in the spinal column that could lead to the vertebra weakening to a point where it slips out of place and requires surgery.

Mettenberger is currently having his back treated non-surgically and surgery shouldn't be necessary anytime soon, but the condition is enough to concern some teams. However, Mettenberger's trainer believes that the back condition will not be a problem.

“Did it flare up in his career? Yes. We would treat it and he’d be fine,” LSU trainer Jack Marucci told NFL.com. “It wasn’t something we thought was a chronic disc or something. He doesn’t need surgery. There’s no surgery for it. He’s worked with our doctors. This shouldn’t be a big deal as long as you treat it, we did some core stabilization. His senior year, we didn’t even talk about it.”

Before Mettenberger's senior year in Baton Rouge, there were rumors that the quarterback had received some form of treatment for a back issue, but the condition did not seem to be a problem for him during the 2013 season.

However, when you mix in the back concerns with his diluted urine sample and the fact that he is coming off a torn ACL, there is a real chance that Mettenberger's chances of being a Day 2 draft selection could be in serious jeopardy.